This patch revamps the wasm backend's JSFFI internal implementation
and documentation:

- `JSValManager` logic to allocate a key is simplified to simple
  bumping. According to experiments with all major browsers, the
  internal `Map` would overflow the heap much earlier before we really
  exhaust the 32-bit key space, so there's no point in the extra
  complexity.
- `freeJSVal` is now idempotent and safe to call more than once. This
  is achieved by attaching the `StablePtr#` to the `JSVal#` closure
  and nullifying it when calling `freeJSVal`, so the same stable
  pointer cannot be double freed.
- `mkWeakJSVal` no longer exposes the internal `Weak#` pointer and
  always creates a new `Weak#` on the fly. Otherwise by finalizing
  that `Weak#`, user could accidentally drop the `JSVal`, but
  `mkWeakJSVal` is only supposed to create a `Weak` that observes the
  `JSVal`'s liveliness without actually interfering it.
- `PromisePendingException` is no longer exported since it's never
  meant to be caught by user code; it's a severe bug if it's actually
  raised at runtime.
- Everything exported by user-facing `GHC.Wasm.Prim` now has proper
  haddock documentation.
- Note [JSVal representation for wasm] has been updated to reflect the
  new JSVal# memory layout.

(cherry picked from commit fd40eaa1)

There's a much more efficient way to convert an unsigned i32 to a
signed one. Thanks, o3-mini-high.

(cherry picked from commit 75fcc5c9)

The wasm dynamic linker used to depend on v8's experimental wasm type
reflection support to generate stub functions when treating GOT.func
items that aren't exported by any loaded library yet. However, as we
work towards wasm ghci browser mode (#25399), we need to ensure the
wasm dyld logic is portable across browsers. So this commit removes
the usage of wasm type reflection in wasm dyld, and it shall only be
added many months later when this feature is widely available in
browsers.

(cherry picked from commit cca68421)

This commit adds a mkWeakJSVal function that can be used to set up a
Weak pointer with a JSVal key to observe the key's lifetime and
optionally attach a finalizer.

(cherry picked from commit 55af20e6)

JSVal has an internal Weak# with the unlifted JSVal# object as key to
arrange its builtin finalization logic. The Weak# used to designate
Unit_closure as a dummy value; now this commit designates the lifted
JSVal closure as the Weak# value. This allows the implementation of
mkWeakJSVal which can be used to observe the liveliness of a JSVal and
attach a user-specified finalizer.

(cherry picked from commit 4f342431)

This commit makes JSVal an abstract type in the export list of
GHC.Wasm.Prim. JSVal's internal representation is supposed to be a non
user facing implementation detail subject to change at any time. We
should only expose things that are newtypes of JSVal, not JSVal
itself.

(cherry picked from commit 8037f487)

This patch makes `putWithTables` avoid overwriting all existing
UserData writers in the handle. This is crucial for GHC API users that
use putWithUserData/getWithUserData for serialization logic that
involve Names.

(cherry picked from commit c331eebf)

This commit attaches an error message to WouldBlockException, for now
the error message consists of the JS async import code snippet that
thunk is trying to block for. This is useful for debugging synchronous
callbacks that accidentally call an async JS function.

(cherry picked from commit 9b54eecb)

This commit updates wasm backend documentation to reflect the new
JSFFI sync exports feature.

(cherry picked from commit edae2874)

This commit repurposes some existing JSFFI test cases to make them
cover JSFFI sync exports as well.

(cherry picked from commit b6ae908b)

This commit implements the synchronous flavour of the wasm backend
JSFFI exports:

- `foreign export javascript "foo sync"` exports a top-level Haskell
  binding as a synchronous JS function
- `foreign import javascript "wrapper sync"` dynamically exports a
  Haskell function closure as a synchronous JS function
- `foreign import javascript unsafe` is now re-entrant by lowering to
  a safe ccall
- Also fix the issue that JSFFI dynamic exports didn't really work in
  TH & ghci (#25473)

(cherry picked from commit 03ebab52)

This commit allows arbitrary label string to appear in a foreign
export declaration, as long as the calling convention is javascript.
Well, doesn't make sense to enforce it's a C function symbol for a
JSFFI declaration anyway, and it gets in the way of implementing the
"sync" flavour of exports.

(cherry picked from commit a204df3a)

This commit fixes the runIO/runNonIO closure type signatures in the
RTS which should be extern StgClosure. This allows us to remove an
unnecessary type cast in the C foreign desugaring logic, as well as
unneeded complications of JSFFI desugaring logic that also needs to
generate C stubs that may refer to those top handler closures.
Otherwise, we'll have to take special care to avoid generating "extern
StgClosure" declarations for them as we would for other closures, just
to avoid conflicting type signature error at stub compile time.

(cherry picked from commit c78d8f55)

ghc-heap defines HalfWord as Word32/Word16 depending on host word
size. For cross GHC with different host/target word sizes, the Binary
instances are incompatible and breaks iserv serialization of any
message type that involves HalfWord, breaking the ghci debugger. This
patch fixes the issue and has been tested to fix ghci debugger
functionality of the wasm backend. Fixes #25420 #25781.

(cherry picked from commit b228fcb5)

GHCi.BreakArray.showBreakArray is not used anywhere, hence the
housecleaning.

(cherry picked from commit 2d6a63ab)

Hadrian used to omit the docs target as a part of binary-dist-dir for
cross targets. This commit enables docs to be built as a part of cross
bindists and it works just fine in CI.

(cherry picked from commit a794e733)

This commit enables building stage1 haddock for cross ghc. Without
this change, hadrian would panic with "Unknown program" error when
building the _build/stage1/bin/cross-prefix-haddock program needed by
the docs-haddock target, even if it only needs to copy from
_build/stage0/bin/cross-prefix-haddock.

(cherry picked from commit 272eaef0)

Fangyi Zhou authored 2 months ago and Cheng Shao committed 2 months ago

- Add new `WasmInstr` constructor `WasmSqrt` for sqrt, corresponding to
  primitivie operations in wasm.
- When lowering CallishMachOp, use `WasmAbs` and `WasmSqrt` for F32 and
  F64 fabs and sqrt.

(cherry picked from commit 64b0d4d0)

Bumps libffi submodule.

(cherry picked from commit c318be56)

This patch adds a note to explain how the magic variables like
`__ghc_wasm_jsffi_dyld` are brought into scope of JSFFI code snippets,
as follow up work of !13583.

(cherry picked from commit f3bfe31e)

For the wasm target, the driver calls `wasm32-wasi-clang
--print-search-dirs` and finds the sysroot directory that contains
libc.so etc, then passes the directory path to dyld. However, when GHC
is configured with -flto as a part of C/C++ compiler flags, the clang
driver would insert a llvm-lto specific directory in the
--print-search-dirs output and the driver didn't take that into
account. This patch fixes it and always selects the non-lto sysroot
directory to be passed to dyld. This is one small step towards
supporting building all cbits with lto for wasm.

(cherry picked from commit 7eea38c8)

This patch fixes wasm dyld script for shared libraries created by llvm
20.x. The __wasm_apply_data_relocs function is now optional and may be
omitted for shared libraries without any runtime relocatable data
segments, so only call __wasm_apply_data_relocs when it's present.

(cherry picked from commit cb60da24)

This patch uses fromAscList (with O(n) complexity) instead of fromList
(with O(nlogn) complexity) in certain Binary instances. It's safe to
do so since the corresponding serialization logic is based on toList
(same as toAscList).

(cherry picked from commit 1c8e608a)

The `InternalCounters` test case fails when ghc is built with
`+debug_ghc`. This patch skips it in that case and allows the
testsuite to pass for the `+debug_ghc` flavour transformer.

(cherry picked from commit 59b9307b)

This patch removes the unused assembleOneBCO function from the
bytecode assembler.

(cherry picked from commit 02794411)

This patch bumps hadrian index-state to fix bootstrap with 9.12.1.

(cherry picked from commit e16eae65)

Mateusz Goślinowski authored 3 months ago and Cheng Shao committed 2 months ago

(cherry picked from commit 14f8a7ec)

amesgen authored 3 months ago and Cheng Shao committed 2 months ago

This fixes the following esbuild error:

    ✘ [ERROR] Could not resolve "node:timers"

        www/ghc_wasm_jsffi.js:66:25:
          66 │     return (await import("node:timers")).setImmediate;
             ╵                          ~~~~~~~~~~~~~

      The package "node:timers" wasn't found on the file system but is built into node. Are you trying
      to bundle for node? You can use "--platform=node" to do that, which will remove this error.

Previously (i.e. after !13503), one had to work around this by passing
`--external:node:timers`.

(cherry picked from commit f6493dbc)

(cherry picked from commit 42826a89)

This patch makes test-bootstrap related ci jobs only depend on
hadrian-ghc-in-ghci job to finish, consistent with other jobs in the
full-build stage generated by gen_ci.hs. This allows the jobs to be
spawned earlier and improve overall pipeline parallelism.

(cherry picked from commit e684c406)

This patch makes some minor improvements re nix-in-docker logic in the
ci configuration:

- Update `nixos/nix` to the latest version
- Apply $CPUS to `cores`/`max-jobs` to avoid oversubscribing while
  allowing a reasonable degree of parallelism
- Remove redundant `--extra-experimental-features nix-command` in
  later `nix shell` invocations, it's already configured in
  `/etc/nix/nix.conf`

(cherry picked from commit 291388e1)

This patch removes the unused `GHC.Linker.Loader.loadExpr` function.
It was moved from `GHC.Runtime.Linker.linkExpr` in `ghc-9.0` to
`GHC.Linker.Loader.loadExpr` in `ghc-9.2`, and remain completely
unused and untested ever since. There's also no third party user of
this function to my best knowledge, so let's remove this. Anyone who
wants to write their own GHC API function to load bytecode can consult
the source code in older release branches.

(cherry picked from commit 536cdf09)

This patch fixes foreign import javascript "wrapper" in wasm backend's
TH/ghci by fixing the handling of dyld/finalization_registry magic
variables. Fixes T25473 and closes #25473.

(cherry picked from commit bd0a8b7e)

This commit adds regression test T25473 marked as broken due to #25473.
It will be fixed in the subsequent commit.

(cherry picked from commit ed2ed6c5)

This patch improves the compile_flags.txt config used to power clangd
for the rts C codebase. The flags in the file are sampled & deduped
from a real stage1 build with clang-19 and vastly improves the IDE
accuracy when hacking the rts.

For maximum code coverage under the default settings,
compile_flags.txt defaults to threaded+profiled+dynamic+debug way.
This does not mean profdyn needs to be actually built in _build/stage1
for IDE to work. To activate IDE for other RTS ways, simply remove one
of the -D flags at the end of compile_flags.txt and restart clangd.

(cherry picked from commit 59e0a770)

This patch fixes one incoherent place between bindist makefile and
hadrian logic: I forgot to include wasi/wasm32 in
OsSupportsGHCi/ArchSupportsGHCi as well. And this results in incorrect
settings file generated after installing the bindist, and "Use
interpreter"/"Have interpreter" fields incorrectly have "NO" values
where they should be "YES" like --info output of in-tree version.

(cherry picked from commit 75a2eae4)

This patch removes the obsolete cross-port script in the tree. The
script was based on the legacy Make build system which has been pruned
from the tree long ago. For hadrian, proper support for two-stage
bootstrapping onto a new unsupported platform is a work in progress in
!11444.

(cherry picked from commit 00d551bf)

This patch fixes FinalizationRegistry related logic for Cloudflare
Workers in wasm backend js post linker. Cloudflare Workers doesn't
support FinalizationRegistry, in this case we use a dummy
implementation that doesn't do anything.

(cherry picked from commit bea8ea4c)

This patch fixes setImmediate() implementation for Cloudflare Workers
in the wasm backend's js prelude script. Cloudflare Workers doesn't
support the MessageChannel API, and we use a setTimeout() based
fallback implementation in this case.

(cherry picked from commit c37b96fa)